Humoral function of acute leukaemic blasts.

Leukamic blasts from 8 patients with different forms of acute leukaemia were investigated for their capability to produce colony stimulating factor. A second point of investigation was to detect inhibitory activity from the same blasts. The agar technique in its double layer modification was used with bone marrow from C57 Bl mice as target cell population. No single pattern of colony growth was observed. CSF production was absent or very low, when compared with CSF from normal mononuclear cells. However, blasts from 4 patients disclosed inhibition of colony growth. No certain relationship existed between the cytochemic type of leukaemia and the production of either activator or inhibitor of in vitro colony formation.